Cooling equipment is one essential component for internal combustion engine as the engine temperature directly affects the overall durability, performance, and manufacture cost. My research has led me in the direction of providing an unlimited compression ratio cooling cylinder combined with a charge-intake to reduce the engine temperature. This self-cooling internal combustion engine requires a basic unit of two four-cycle power cylinders and one cooling cylinder and a charge-intake device to utilize energy of power stroke and exhaust to cool down the temperature of the engine head from within after combustion process of each power stroke completes. Said two power cylinders are arranged with 180 degree of crankshaft rotation apart and said cooling cylinder is trailing the primary power cylinder by approximately 90 degree of crankshaft rotation; said cooling cylinder initiate a flow of compressed cool air into each power cylinder approximately 60 degree of crankshaft rotation after ignition of each power cylinder. The working medium within the power cylinder is approximately over 2000 degree for gasoline right after the ignition, when the compressed cool air flows into the power cylinder, the compressed cool air is blown up onto the inner surface of the engine head, creating a cool air barrier beneath the inner surface of the engine head and absorbing the heat of the combustion, therefore the engine head temperature and exhaust temperature is greatly reduced.
The prior art shows that various inventors have suggested a structure consisting of two four-cycle power cylinders and one air-fuel charging cylinder; one representative of such structure is U.S. Pat. No. 4,202,300, the major differences between these types of engines and the present invention are that the charging cylinder of the prior art requires variable volume and fuel input, and the objective is to force additional air-fuel mixture into the power cylinder before the ignition of power cylinders, these types of engines utilize the charging cylinder to increase the amount of air-fuel mixture in each combustion process thereby increasing the engine temperature and power output. Another significant difference is that the size of the cooling cylinder of the present invention is approximately the same as that of the power cylinders for cooling purpose while other prior art has a relatively small charging cylinder for air-fuel compressing purpose.
Another type of engine structure shown in the prior art has one primary cylinder connected to one secondary power cylinder, even though the secondary power cylinder only has air input, the objective of this type of engine is to prolong the combustion process and increase the fuel economy. The major difference is that the basic structure of the present invention is based on a concept of dual six-stroke operation, and the cooling cylinder only provides cooling effect to the engine, the cooling cylinder cannot provide any power output while the objective of the prior art is to generate power output from both primary and secondary power cylinders.
The most preferable type of charge-intake of the present invention is a turbo type. The exhaust ports of the primary power cylinder and the secondary power cylinder are connected to the input side of the turbo, while the compressor discharge side of the turbo is connected to the cooling cylinder; this is also another objective to the present invention to utilize energy of the exhaust to cool down the engine from within, this embodiment can possibly eliminate the needs for additional cooling equipments such as radiators and intercoolers, therefore its applications can extend to the vehicle engines running on severe condition territory such as desert. Since the need of radiator is eliminated, the engine reliability under severe weather condition is greatly improved.
It is also possible to employ a super-charge or other type of charge-intake on the present invention for other applications. For small engines such as the one powering a lawn mower, the cost of the intake-charge might over-weigh the value of the engine, the engine can still be constructed with normal air-intake.